Automatic circuit breaker with spring and link connection of handle to actuator



T. M. COLE July 27, 1954 T BREAKER WITH SPRI LINK CONNECTION OF HANDL 2,685,009 AUTOMATIC CIRCUI NG AND E TO ACTUATOR Filed June 29, 1951 INVENTOR. THO/14,46 M. 60.45

Patented July 27, 1954 AUTOMATIC CIRCUIT BREAKER WITH SPRING AND LIN HANDLE TO ACT K CONNECTION OF UATIOR Thomas M. Cole, New York, N. Y., assignor to Federal Electric Products Company, Newark,

a. corporation of Delaware Application June 29, 1951, Serial No. 234,304

20 Claims. 1

The present invention relates to automatic circuit breakers, and more particularly to circuit breakers of the type in which an actuator is pivotally carried by the movable contact member and is latched thereto, under the control of a current-responsive device, for the manual operation of the circuit breaker to open and close it. A circuit breaker of the general type to which the present invention relates is shown in the United States Patents Nos. 2,174,669, 2,209,319, 2,209,351, 2,209,352, 2,209,353, and Re. No. 23,188. In a circuit breaker of the general character disclosed in the aforementioned patents, provision should be made for resiliently acting means for insuring the required contact pressure for proper engagement between the companion contacts of the circuit breaker when the breaker is closed. As disclosed in Patent No. 2,209,351, the contacts themselves may be resiliently mounted. In Patent No. 2,209,352 the desired result is achieved by providing a resilient link which connects the handle to the actuator. In the copending application of Paul M. Christensen, Ser. No. 221,420 filed April 17, 1951 and assigned to the assignee hereof, the required contact pressure is achieved by providing for limited bodily movement of the movable contact member on a floating pivot. Pursuant to the present invention, it is unnecessary to resiliently mount the contacts, as in Patent No. 2,209,351, and it is also unnecessary to provide for limited bodily movement of the movable contact member, as in said copending application. Furthermore, it is unnecessary to provide a resilient link between the handle and the actuator for the movable contact member. The elimination of the requirement for a resilient link between the handle and the releasably latched switch actuator is obviated, pursuant to the present invention, whereby the connection between the handle and the actuator can be constituted by a rigid link, if desired, and yet a resilient mounting of the contacts, or limited bodily movement of the movable contact member on a floating pivot, is not required.

Another object of this invention is to provide a resilient connection between the handle and a link connected to the actuator for operating the latter manually, while the actuator is latched to the movable contact member by the currentresponsive device which trips the circuit breaker upon overload, so that the movable contact is resiliently biased toward and pressed against the stationary contact to compensate for wear and inequalities, and to provide means which act positively on said actuator to reset the latter after the circuit breaker is tripped upon the occurrence of an overload.

Pursuant to the present invention and an object thereof, a spring means is operable upon a rigid link interconnected between the handle and the actuator, when the circuit breaker is closed, to bias the movable contact member to resiliently press the movable contact against the sta tionary contact for proper contact pressure to compensate for wear of the contacts or for other inequalities, the connection between the link and the handle, however, being such that the actuator is positively acted upon for the resetting thereof after the circuit breaker is tripped upon the occurrence of an overload.

The above and. other objects, features and advantages of the present invention will be more fully understood from the following description considered in connection with the accompanying drawings.

In the drawings:

Fig. 1 is a side View of a circuit breaker embodying the present invention, one of the casing parts being removed for the purpose of illustration, the circuit breaker mechanism being shown open;

Fig. 2 is a view similar to broken away, anism closed;

Fig. 3 is a sectional View, on an enlarged scale, taken on the line 33 of Fig. 1;

Fig. 4 is a sectional view on a reduced scale, taken on the line 4-4 of Fig. 3;

Fig. 5 is a sectional view taken on 55 of Fig. 4;

Fig. 6 is an end view of the circuit breaker, both casing parts being in place; and

Fig. 7 is a sectional view taken on the line 17 of Fig. 1.

Referring now to the drawings in detail, the circuit breaker embodying the present invention comprises a two-part insulating casing having the complementary molded parts l0 and [2 in which the terminals [4 and I6, and the circuit breaker mechanism are mounted, as described, for example, in my copending application Ser. No. 127,433 filed November 15, 1949, now Patent No. 2,647,186, dated July 28, 1953, and in the copending application Ser. No. 217,162 filed March 23, 1951 by Paul M. Christensen and myself, now Patent No. 2,642,509, dated June 16, 1953. It will be understood that the two casing parts 30 and I2 are held together by bolts, or other suitable means, passing through openings I8 in Fig. 1, with parts showing the circuit breaker mechthe line 3 casing part Ill and similar openings in casing part !2 which register with said openings 58 when the two casing parts are in assembled relation. While as here shown, the terminal member I6 is in the form or" a prong of the plug-in type, as described in the above mentioned Patent No. 2,647,186, it will be understood that this is not essential to the present invention but on the contrary a different type of terminal member can be provided instead.

The stationary contact 29 is carried by the terminal member H3 in a position within the easing to be engaged by the movable contact 22 carried by the movable contact member 255. Said movable contact member is mounted on a pivot 26 for pivotal movement between the casing parts and IE to and from the circuit closed position, illustrated in 2, in which contact engages the stationary contact 26, and to and from the circuit open position, illustrated in Fig. l, in which said movable contact 22 is shown disengaged from said stationary contact 29. For this purpose, the pivot 26, as illustrated in Fig. 3, is mounted in suitable bearing apertures 28 and 3E! provided in the casing parts In and I2, respectively. Said pivotal movement of the movable contact member may be accomplished manually by the handle 32 which is operatively connected to the channel-shaped actuator 34 by a U-shaped link 36 which is pivotally connected at one end thereof to said actuator, and at its opposite end to a cylindrical member or sleeve 38 carried by the handle, as will hereinafter be more specifically described. The actuator 34 is pivotally mounted on the movable contact member, as indicated at and is operatively connected to the movable contact member 24 for moving the latter, under the control of the current responsive latch 42 which includes a bimetallic strip 44, and an electromagnet device 46, 18 by which said actuator 3A is releasably latched to the movable contact member 2a, as described in my above-mentioned Patent No. 2,647,136 and in patent Re. No. 23,188. As here shown, a pe'ipherally interrupted opening 5c is provided at the edge of the movable contact member 24. Said opening is adapted, as described in detail in my copending application Ser. No. 213,591 filed March 2, 1951, now Patent No. 2,647,187, dated July 28, 1953,

to receive a suitable tool in order to displace a part of the movable contact member in its own plane to adjust the relative disposition of the actuating means and the latch for calibration purposes. However, it will be understood that this method of calibration i not essential to the present invention, but on the contrary, the circuit breaker may be otherwise calibrated, for example,

as illustrated and described in said patent Re. No. 23,188 wherein provision is made in the movable contact member ior a slot, a screw being adjustable therein for calibrating the circuit breaker.

It will be understood that, as illustrated in Fig. 2, when the handle 32, is in the On or circuit closed position thereof, and the actuator 34 is latched to the movable contact member 24 by engagement with the outer end of the bimetallic strip 44, as shown, relative pivotal movement of the movable contact member is prevented and contact 22 is in engagement with the contact 253. In this position, the link 36, which pursuant to the present invention may be comparatively nonresilient, and the actuator 34, are in overset toggle condition. It will be understood that link 3% is sufliciently non-resilient to perform its function of returning the actuator 3 to a reset position thereof, relative to the latch 52, upon tripping of the circuit breaker. In order for the circuit breaker to open either automatically, that is, pursuant to the flexing of the bimetal strip it, either upon heating thereof or by the attraction of member it to the armature d8 of the electromagnet, the toggle must be broken and this can take place either by movement of the handle 32 to its circuit-open position, as illustrated in Fig. l, manually or by release of the end ii-iA of the actuator the bimetal strip is when the circuit breaker trips upon overload or other predetermined load conditions. The opening of the circuit breaker when the latch releases the actuator 34 is effected by the spring 52 which is connected at one end thereof to the handle part 1%, and which i connected at its other end to the part 5% of the movable contact member. It will be observed that said spring is compressed in the circuit closed condition of the circuit breaker so as to bias the movable contact member 2a to the circuit open position and to move the latter to said position when the latch A 2 disengages the actuator 3 Also, it will be noted that said spring is effective to move the handle 32 to its Off or circuit open position when the circuit breaker is tripped, that is when the movable contact member moves to a circuit open position pursuant to the release of actuator 34 by latch 42. Further, it will be observed that even though the handle is held in the On position thereof, said spring is effective to open the circuit breaker when the latter is tripped, that is, when the latch 42 disengages the actuator 34-. In order to prevent the possible buckling of said spring in the circuit closed condition thereof, the casing part it is provided with the projecting portion 58 carried by the bearing portion 3i? of said casing part, the relative disposition of the spring 52 and the projection 53 in the circuit closed condition of the circuit breaker being indicated in Fig. 2.

Pursuant to the present invention, the movable contact 22 is resiliently pressed against the stationary contact 26 when the circuit breaker is closed. In order to accomplish this purpose, the link 33 is operatively connected to the handle 32 by means of the previously mentioned preferably metallic cylinder or sleeve 38 which in turn is resiliently mounted in the handle 32. In order to effect said resilient mounting of the cylinder 32, the handle is provided with an internal passageway 68 which extends longitudinally between the laterally extending pivot portions 62 and 64 thereof. The aforementioned sleeve 38 is disposed in said passageway, the resilient mounting thereof being accomplished by a compression spring E5 disposed therein. More specifically, one end of said spring 36 is carried by the pressed-in shoulder portions 53 of the sleeve, the other end thereof extending outwardly of the sleeve and abutting the closed end 'ifi of the passageway 60. It will be noted that the end '52 of the sleeve 38 extends outwardly of the open end E5 of the passageway 65. It will be understood that the sleeve 38 has limited bodily movement in a direction axially thereof within the passageway 68, the maximum inward movement of said sleeve being limited by the full compression of the spring 65 or the closed end it of the passageway and the maximum outward movement of the sleeve being limited by the engagement of the ear 78 (Fig. 3) carried thereby in a V-shaped or notched portion it of the handle 32.

In order to mount the sleeve 38 and the spring 66 carried thereby in the handle 32, the latter is provided with a longitudinally extending slot 80 which is parallel to the aforesaid passageway 60, and which extends inwardly from the open end i l of the latter. As best illustrated in Fig. 5, it will be noted that the slot 80 is radially disposed by 90 from the aforementioned notch 18. In inserting the sleeve 38 and the spring 36 into the handle 32, the spring is first positioned Within the sleeve so that the lower end thereof is disposed on the aforementioned shoulder portions 68. The sleeve is then inserted into the passageway Sll through the open end 14 thereof, with the car '16 disposed in the slot 80 which is dimensioned to slidably receive the ear. The sleeve is then urged into the handle until the ear l6 clears the inner end of the slot 80 whereupon the sleeve is rotated by 90 until the ear 16 is engaged in the V-shaped notch '58. It will be apparent that due to said engagement of the ear in the V-shaped notch, turning movement of the sleeve within the handle is prevented, the ear 16 being biased into the notch by the spring 66 which is under partial compression when the sleeve is disposed within the handle, as illustrated in Fig. 3. In said position, it will be noted that the inner end 82 of the sleeve is spaced from the handle portion 10.

In order to provide for the operative connection of the handle 32 to the actuator 34, the sleeve is provided with the aligned apertures 84 and 86 and it will be understood that when the car 76 is disposed within the notch 18, as previously described, the apertures 84 and 86 are properly positioned relative to the aligned apertures 88 and 98 in the channel-shaped actuator 34, as best illustrated in Fig. '7, so that the U-shaped link 36 may be readily inserted in the sleeve and in the channel-shaped actuator to interconnect the handle and the actuator for the manual operation of the latter, as previously described.

When the circuit breaker mechanism is in the circuit closed position thereof, so that the link 36 and the actuator 34 are in overset toggle condition as previously described, it will be noted that the sleeve 38 is disposed inwardly of the handle 32 from the position thereof in the open condition of the circuit breaker. It will be apparent that said inward positioning of the sleeve results in the further compression of the spring 8 whereby the latter applies a resilient spring pressure through the aforementioned toggle which biases the movable contact member 24 in a clockwise direction thereof, viewing Fig. 2, whereby to provide the required resilient pressure between the movable contact 22 and the stationary contact '29 to compensate for wear or other inequalities. In addition to the previously described toggle, it Will be noted that the resiliently mounted sleeve 38 and the comparatively nonresilient link 36 are connected to each other in toggle-link fashion for operating actuator 34 to close the circuit breaker and to provide a resilient pressure between contacts 20 and 22 in the closed condition of the circuit breaker. Upon tripping of the circuit breaker, due to overload or other abnormal current conditions, the spring 52, in addition to causing the disengagement of the contact 22 from the contact 26, will also, as previously described, be effective to move the handle to the of? position thereof, illustrated in Fig. 1. Said movement of the handle will result in the concomitant movement of the sleeve 32 which is rigidly mounted therein, so far as lateral movement of the sleeve relative to the handle is concerned, whereby to provide means for positively causing the actuator 34 to rotate in a counterclockwise direction, viewing Fig. 2, through the operation of said sleeve upon the link 36, whereby the actuator is carried to the position thereof illustrated in Fig. 1. It will be observed that in said position, the actuator is automatically disposed in a reset position thereof to engage the bimetal strip 44 upon movement of the handle to the On position thereof, as illustrated in Fig. 2.

The subject matter of the present application is related to the subject matter of the copending application of Paul M. Christensen, Serial No. 234,297, filed June 29, 1951, now Patent No. 2,662,950, dated December 15, 1953 and assigned to the assignee hereof.

While I have shown and described the preferred embodiment of my invention, it will be understood that various changes may be made in the present invention without departing from the underlying idea or principles of the invention within the scope of the appended claims.

Having thus described my invention, what I claim and desire to secure by Letters Patent, is:

1. In an automatic circuit breaker having a stationary contact, a movable contact member having a contact engageable with and disengageable from said stationary contact, a current responsive latch, an actuator mounted on said contact member and operatively connected thereto, under the control of said latch, for closing the circuit breaker, a manually operable handle, and a connection operative between said handle and said actuator whereby said handle is effective to operate said actuator, that improvement which comprises resilient means between said handle and said connection operable when said actuator is latched to said movable contact member and said contacts are in engagement for resiliently biasing the movable contact toward said stationary contact whereby to provide resilient contact pressure between said contacts in the closed condition of the circuit breaker.

2. In an automatic circuit breaker having a stationary contact, a movable contact member having a contact engageable with and disengageable from said stationary contact, a current responsive latch, an actuator mounted on said contact member and operatively connected thereto, under the control of said latch, for closing the circuit breaker, and a manually operable handle, a connection between said handle and said actuator comprising a resilient member and a comparatively non-resilient member operatively connected to said handle and actuator, respectively, and operatively connected to each other in toggle-link fashion for operating said actuator to close the circuit breaker and to provide a resilient pressure between said contacts in the closed condition of the circuit breaker.

3. In an automatic circuit breaker having a stationary contact, a movable contact member having a contact engageable with and disengageable from said stationary contact, a current responsive latch, an actuator mounted on said contact member and operatively connected thereto, under the control of said latch, for closing the circuit breaker, and a manually operable handle, a connection between said handle and said actuator comprising a resilient member and a comparat-ively non-resilient member, operatively connected to each other and to said handle and actuator, respectively, for operating said actuator to close the circuit breaker and to provide a resilient pressure between said contacts in the closed con- 7; dition orthe circuit breaker, said resilient memher, being mounted on said handle and bodily movabletherewith.

l. In an automatic circuit breaker having a stationary contact, a movable contact member having a contact engageable with anddisengageablerrom said stationary contact, a current responsive latch, an actuator mounted on said contact member and operatively connected thereto, under the control of said latch, for closing the circuit breaker, and a manually operable handle, a connection between said handle-and said actuator comprising a resilient member and a comparatively non-resilient member operatively connected to said handle and actuator, respectively, and operatively connected to each other in togglelink fashion for operating said actuator to close the circuit breaker and to provide a resilient pressure between said contacts in the closed condition of the circuitbreaker, said resilient member being mounted on said handle and bodily movable therewith.

5. in an automatic circuit breaker having a stationary ontact, a movable contactmeinber having a'c'ontact engageable with and disengageable from said stationary contact, a, current responsive latch, an actuator mounted on said contact member and operatively connected thereto,

under the control of said latch, for closing the circuit breaker, and a manually operable handle, mechanism operatively connecting said handle to said actuator including spring means mounted on said handle and bodily movable therewith for operating said actuator to close the circuit breaker and to provide a resilient pressure between said contacts in the closed condition of the circuit breaker.

6. In an automatic circuit breaker having a stationary contact, a movable contact member having a contact engageabie with and disengageable from said stationary contact, a current responsive latch, an actuator mounted on said contact member and'operatively connected .thereto, under the control of said latch, for closing the circuit breaker, a manually operable handle, and a connectionoperative between said handle and said actuator whereby said handleis effective to actuate said actuator, that improvement which comprises resilient means between said handle and said connection operable when said actuator is latched to said movablelcontact member and said contacts are in engagement forresiliently iasing the movable contact toward said stationary contactwhereby to provide resilient contact pressurebetween said contacts in the closed condition of the circuit breaker, said connection being a link having one end connected to said actuator, and said resilient'means including a spring inoperative engagement with the other end of said link for biasing said link in the closed condition of the circuit breaker.

"I. A circuit breaker, as defined in claim 6, further characterized in that said link is a comparative non-resilient member.

8. In an automatic circuit breaker havinga stationary contact, a movable contact member having a contact engageable with and disengageable from said stationary contact, a current responsive latch, an actuator mounted on said contact member and operatively connected thereto,

under the control of said latch, for closing the circuit breaker, a manually operable handle, and a connection operative between said handle and said actuator whereby said handle is eifective to operate said actuator, that improvement which comprises resilientmeans between said handle 3 and saidconnectionoperable whensaid actuator is latched to said movable contact member and saidcontacts are in engagement for resiliently biasing the movablecontact toward said stationarycontact whereby to provide resilient contact pressure between said contacts in the closed condition of the circuit breaker, said connection being a link having one end connected to said actuator, and said resilient means including a spring in operative engagement with the other end of said link for biasing said link in the closed condition of the circuit breaker, said resilient means also including a rigid member interconnecting said handle and said other end of said link, said rigid member being effective through said iink to move said actuator to a predetermined position in relation to said current responsive latch to reset said actuator following the automatic opening of the circuit breaker.

9..In an automatic circuit breaker having. a stationary contact, a movable contact member having a contact engageabie with and disengageable from said stationary contact, a current responsive latch, and an actuator mounted on said contact member and operatively connected there- 'to, under the control of said latch, for closing the circuit breaker, manually operable handle having an operative connection with said actuator for actuating the latter, said connection comprising link means having one end thereof connected to said actuator, and spring means carried by said handle and in operative engagement with the other end of said link means, said spring means being effective, when said actuator is latched to said movable contact member and said contacts are in engagement for resiliently biasing the movable contact toward said stationary contact whereby to provide resilient contact pressure between said contacts in the closed condition of the circuit breaker.

1c. In anautomatic circuit-breaker having a stationary contact, a movable contact member having a contact engageable with and disengageable from saidstationary contact, a current responsive latch, and an actuator mounted on said contact member and operatively connectedthereto,under the control of saidlatch, ior-closing the circuit breaker, a manually operable handle having an-operative connection with said-actuator for actuating the latter, said connection comprising link means having one end thereof connected to said actuator, and spring means carried by said handle and in operative engagement with the other end of said link means, said spring means bein effective, when said actuator is latched to said movable contact member and said contacts are in engagement for resiliently biasing the movable contact toward saidustationary contact whereby to provide resilient contact pressure between said contacts in the closed condition of the circuit breaker, said spring means and said link means being operatively. connected to each other in toggle-link fashion.

11. In an automatic circuit breaker. having a stationary contact, a movable contact member having a contact engageable with and disengageable from said stationary contact, a current responsive latch, and an actuator mounted on said contact memberiand operatively connected thereto, under the control 01' said latch, for closing the circuit breaker, a manually operable handle having an operative connection with said actuator for actuating the latter, said connection comprising a link having one end thereof connected to said actuator, and a spring mounted on; said handle and in -operative engagement withthe other end of said link, said spring being efiective, when said actuator is latched to said movable contact member and said contacts are in engagement for resiliently biasing the movable contact toward said stationary contact whereby to provide resilient contact pressure between said contacts in the closed condition of the circuit breaker, said handle being provided with a sleeve, said other end of said link being engaged in said sleeve, said spring being carried by said sleeve and the latter being mounted for axial movement on said handle for compressing said spring in the closed condition of the circuit breaker.

12. In an automatic circuit breaker having a stationary contact, a movable contact member having a contact engageable with and disengageable from said stationary contact, a current responsive latch, and an actuator mounted. on said contact member and operatively connected thereto, under the control of said latch, for closing the circuit breaker, a manually operable handle having an operative connection with said actuator for actuating the latter, said connection comprising a link having one end thereof connected to said actuator, and a spring mounted on said handle and in operative engagement with the other end of said link, said spring being effective, when said actuator is latched to said movable contact member and said contacts are in engagement for resiliently biasing the movable contact toward said stationary contact whereby to provide resilient contact pressure between said contacts in the closed condition or the circuit breaker, and means provided on said handle and operative upon said link for moving said actuator positively in one direction to a reset position following the automatic opening of the circuit breaker.

13. In an automatic circuit breaker having a stationary contact, a movable contact member having a contact engageable with and disengageable from said stationary contact, a current responsive latch, and an actuator mounted on said contact member and operatively connected thereto, under the control or" said latch, for closing the circuit breaker, a manually operable handle having an operative connection with said actuator for actuating the latter, said connection comprising a link having one end thereof connected to said actuator, and a spring mounted on said handle and in operative engagement with the other end of said link, said spring being effective, when said actuator is latched to said movable contact member and said contacts are in engagement for resiliently biasing the movable contact toward said stationary contact whereby to provide resilient contact pressure between said contacts in the closed condition of the circuit breaker, and a rigid member mounted for axial movement on said handle and extending therefrom, said rigid member mounting said spring and being connected to said other end of said link.

14. In an automatic circuit breaker having a stationary contact, a movable contact member having a contact engageable with and disengageable from said stationary contact, a current responsive latch, and an actuator mounted on said contact member and operatively connected there to, under the control of said latch, for closing the circuit breaker, a manually operable handle having an operative connection with said actuator for actuating the latter, said connection comprising a link having one end thereof connected to said actuator, and a spring carried by said handle and in operative engagement with the other end of said link, said spring being eiiective,

when said actuator is latched to said movable contact member and said contacts are in engagement for resiliently biasing the movable contact toward said stationary contact whereby to provide resilient contact pressure between said con tacts in the closed condition of the circuit breaker, a rigid member mounted in said handle and extending therefrom, said rigid member mounting said spring and being connected to said other end of said link, said handle having a passageway in which said rigid member is axially movable for compressing said spring, and said handle having a portion engageable with said rigid member for retaining and positioning the latter therein.

15. In an automatic circuit breaker having a stationary contact, a movable contact member having a contact engageable with and disengageable from said stationary contact, a current responsive latch, and an actuator mounted on said contact member and operatively connected there to, under the control of said latch, for closing the circuit breaker, a manually operable handle having an operative connection with said actuator for actuating the latter, said connection comprising a link having one end thereof connected to said actuator, and a spring carried by said handle and in operative engagement with the other end of said link, said spring being efiective, when said actuator is latched to said movable contact member and said contacts are in engagement for resiliently biasing the movable contact toward said stationary contact whereby to provide resilient contact pressure between said con tacts in the closed condition of the circuit breaker, a rigid member mounted in said handle and extending therefrom, said rigid member mounting said spring and being connected to said other end of said link, said handle having a passageway in which said rigid member is axially movable,

said passageway being closed at one end thereof and said spring being disposed therein for compression by said rigid member, said rigid member being moved toward said closed end in the closed condition of the circuit breaker.

16. In an automatic circuit breaker having a stationary contact, a movable contact member having a contact engageable with and disengageable from said stationary contact, a current responsive latch, and an actuator mounted on said contact member and operativcly connected thereto, under the control of sai latch, for closing the circuit breaker, a manually operable handle having an operative connection with said actuator for actuating the latter, said connection compris ing a link having one end thereof connected to said actuator, and a spring carried by said handle and in operative engagement with the other end of said link, said spring bein effective, when said actuator is latched to said movable contact member and said contacts are engagement for resiliently biasing the movable contact toward said stationary contact whereby to provide resilient contact pressure between said contacts in the closed condition of the circuit breaker, a sleeve mounted in said handle and extending therefrom, said sleeve mounting said spring and being connected to said other end of said link, said handle having a passageway in which said sleeve is axially movable, said sleeve having a part engageable with a handle portion for retaining said sleeve therein, said portion being adapted to retain said sleeve against turning movement and being disposed to automatically position said sleeve relative to said actuator whereby to facili- 

